What is the vertex of the graph of this equation y=-4x2 - 16x - 12?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

20.ju inces. which ordered pair is a viable solution if x represents the number of books he orders and y represents the total weight of the books, in ounces? (-3,-18) (-0.5, -3) (0,0) (0.5, 3)

*segment an is an altitude of right ? abc with a right angle at a. if ab = 2root 5 in and nc = 1 in, find bn, an, ac.